Tags

Type your tag names separated by a space and hit enter

Aerobic exercise training induces skeletal muscle hypertrophy and age-dependent adaptations in myofiber function in young and older men.
J Appl Physiol (1985). 2012 Nov; 113(9):1495-504.JA

Abstract

To examine potential age-specific adaptations in skeletal muscle size and myofiber contractile physiology in response to aerobic exercise, seven young (YM; 20 ± 1 yr) and six older men (OM; 74 ± 3 yr) performed 12 wk of cycle ergometer training. Muscle biopsies were obtained from the vastus lateralis to determine size and contractile properties of isolated slow [myosin heavy chain (MHC) I] and fast (MHC IIa) myofibers, MHC composition, and muscle protein concentration. Aerobic capacity was higher (P < 0.05) after training in both YM (16 ± 2%) and OM (13 ± 3%). Quadriceps muscle volume, determined via MRI, was 5 ± 1 and 6 ± 1% greater (P < 0.05) after training for YM and OM, respectively, which was associated with an increase in MHC I myofiber cross-sectional area (CSA), independent of age. MHC I peak power was higher (P < 0.05) after training for both YM and OM, while MHC IIa peak power was increased (P < 0.05) with training in OM only. MHC I and MHC IIa myofiber peak and normalized (peak force/CSA) force were preserved with training in OM, while MHC I peak force/CSA and MHC IIa peak force were lower (P < 0.05) after training in YM. The age-dependent adaptations in myofiber function were not due to changes in protein content, as total muscle protein and myofibrillar protein concentration were unchanged (P > 0.05) with training. Training reduced (P < 0.05) the proportion of MHC IIx isoform, independent of age, whereas no other changes in MHC composition were observed. These data suggest relative improvements in muscle size and aerobic capacity are similar between YM and OM, while adaptations in myofiber contractile function showed a general improvement in OM. Training-related increases in MHC I and MHC IIa peak power reveal that skeletal muscle of OM is responsive to aerobic exercise training and further support the use of aerobic exercise for improving cardiovascular and skeletal muscle health in older individuals.

Authors+Show Affiliations

Human Performance Laboratory, Ball State University, Muncie, Indiana 47306, USA. mharber@bsu.eduNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, N.I.H., Extramural
Research Support, U.S. Gov't, Non-P.H.S.

Language

eng

PubMed ID

22984247

Citation

Harber, Matthew P., et al. "Aerobic Exercise Training Induces Skeletal Muscle Hypertrophy and Age-dependent Adaptations in Myofiber Function in Young and Older Men." Journal of Applied Physiology (Bethesda, Md. : 1985), vol. 113, no. 9, 2012, pp. 1495-504.
Harber MP, Konopka AR, Undem MK, et al. Aerobic exercise training induces skeletal muscle hypertrophy and age-dependent adaptations in myofiber function in young and older men. J Appl Physiol. 2012;113(9):1495-504.
Harber, M. P., Konopka, A. R., Undem, M. K., Hinkley, J. M., Minchev, K., Kaminsky, L. A., Trappe, T. A., & Trappe, S. (2012). Aerobic exercise training induces skeletal muscle hypertrophy and age-dependent adaptations in myofiber function in young and older men. Journal of Applied Physiology (Bethesda, Md. : 1985), 113(9), 1495-504. https://doi.org/10.1152/japplphysiol.00786.2012
Harber MP, et al. Aerobic Exercise Training Induces Skeletal Muscle Hypertrophy and Age-dependent Adaptations in Myofiber Function in Young and Older Men. J Appl Physiol. 2012;113(9):1495-504. PubMed PMID: 22984247.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Aerobic exercise training induces skeletal muscle hypertrophy and age-dependent adaptations in myofiber function in young and older men. AU - Harber,Matthew P, AU - Konopka,Adam R, AU - Undem,Miranda K, AU - Hinkley,James M, AU - Minchev,Kiril, AU - Kaminsky,Leonard A, AU - Trappe,Todd A, AU - Trappe,Scott, Y1 - 2012/09/13/ PY - 2012/9/18/entrez PY - 2012/9/18/pubmed PY - 2013/4/13/medline SP - 1495 EP - 504 JF - Journal of applied physiology (Bethesda, Md. : 1985) JO - J. Appl. Physiol. VL - 113 IS - 9 N2 - To examine potential age-specific adaptations in skeletal muscle size and myofiber contractile physiology in response to aerobic exercise, seven young (YM; 20 ± 1 yr) and six older men (OM; 74 ± 3 yr) performed 12 wk of cycle ergometer training. Muscle biopsies were obtained from the vastus lateralis to determine size and contractile properties of isolated slow [myosin heavy chain (MHC) I] and fast (MHC IIa) myofibers, MHC composition, and muscle protein concentration. Aerobic capacity was higher (P < 0.05) after training in both YM (16 ± 2%) and OM (13 ± 3%). Quadriceps muscle volume, determined via MRI, was 5 ± 1 and 6 ± 1% greater (P < 0.05) after training for YM and OM, respectively, which was associated with an increase in MHC I myofiber cross-sectional area (CSA), independent of age. MHC I peak power was higher (P < 0.05) after training for both YM and OM, while MHC IIa peak power was increased (P < 0.05) with training in OM only. MHC I and MHC IIa myofiber peak and normalized (peak force/CSA) force were preserved with training in OM, while MHC I peak force/CSA and MHC IIa peak force were lower (P < 0.05) after training in YM. The age-dependent adaptations in myofiber function were not due to changes in protein content, as total muscle protein and myofibrillar protein concentration were unchanged (P > 0.05) with training. Training reduced (P < 0.05) the proportion of MHC IIx isoform, independent of age, whereas no other changes in MHC composition were observed. These data suggest relative improvements in muscle size and aerobic capacity are similar between YM and OM, while adaptations in myofiber contractile function showed a general improvement in OM. Training-related increases in MHC I and MHC IIa peak power reveal that skeletal muscle of OM is responsive to aerobic exercise training and further support the use of aerobic exercise for improving cardiovascular and skeletal muscle health in older individuals. SN - 1522-1601 UR - https://www.unboundmedicine.com/medline/citation/22984247/Aerobic_exercise_training_induces_skeletal_muscle_hypertrophy_and_age_dependent_adaptations_in_myofiber_function_in_young_and_older_men_ L2 - http://www.physiology.org/doi/full/10.1152/japplphysiol.00786.2012?url_ver=Z39.88-2003&amp;rfr_id=ori:rid:crossref.org&amp;rfr_dat=cr_pub=pubmed DB - PRIME DP - Unbound Medicine ER -